About Heterotheca angustifolia (Rydb.) G.L.Nesom
Commonly called hairy golden aster, Heterotheca angustifolia (Rydb.) G.L.Nesom grows between 5 and 70 centimeters (2 to 28 inches) tall, with a more typical height range of 16 to 40 centimeters (6 to 16 inches). Its leaves can reach up to 60 centimeters (24 inches) in length, but most often measure 22 to 40 centimeters (9 to 16 inches) long. It blooms from May to October, producing flower heads roughly 2.5 centimeters (1 inch) wide that contain both yellow ray florets and yellow disk florets. Its seeds have white bristles at their tip. This species can be hard to identify, as it has many close relatives and numerous varieties. The recorded varieties of this species are: Heterotheca villosa var. ballardii (Rydb.) Semple, native to the northern Great Plains in the United States and Canada; Heterotheca villosa var. depressa (Rydb.) Semple, native to Wyoming; Heterotheca villosa var. foliosa (Nutt.) V.L.Harms, found in the Rockies, Black Hills, northern Cascades, and other nearby areas; Heterotheca villosa var. minor (Hook.) Semple, found in the Rockies, Cascades, Sierra Nevada, and other nearby areas; Heterotheca villosa var. nana (A.Gray) Semple, found in the Rockies and other mountain ranges stretching from South Dakota to Arizona; Heterotheca villosa var. pedunculata (Greene) V.L.Harms ex Semple, native to Arizona, New Mexico, Colorado, and Utah; Heterotheca villosa var. scabra (Eastw.) Semple, found in Mexico and the southwestern United States; Heterotheca villosa var. sierrablancensis Semple, native to New Mexico; and Heterotheca villosa var. villosa, found in the northern Great Plains, Columbia Plateau, and other nearby areas. This species is widespread across central and western North America, ranging from Ontario west to British Columbia, and south to Illinois, Kansas, Nuevo León, Guanajuato, and northern Baja California. It grows successfully in dry areas, and can also be found on plains, rocky slopes, cliffs, at low elevations, and within coniferous forests. Wildflower gardener Claude A. Barr considered this plant useful for garden cultivation, thanks to its abundant masses of bright yellow flowers.
